Lactuca indica extract interferes with uroepithelial infection by Escherichia coli

Uropathogenic Escherichia coli is the major cause for urinary tract infections (UTI). Due to emerging antimicrobial resistances treatment of UTI is becoming increasingly difficult. Therefore, alternative treatment strategies are required. We sought to investigate the molecular mechanisms of a traditionally used decoction from Vietnamese dandelion (Lactuca indica L.) mediating local protection of the bladder epithelium.

To study the influence of herbal preparations on the interaction between bladder epithelial cells and uropthogenic Escherichia coli, a cell culture model of UTI was applied. In addition, the direct effect of the herbal extract on Escherichia coli was analyzed.

Although no direct antibacterial activity was determined, Lactuca indica decreased bacterial colonization of bladder epithelial cells remarkably. Reduced bacterial adherence was accompanied by lowered activation of focal adhesion kinase (FAK) in Lactuca indica exposed cells. Treatment with a chemical FAK inhibitor supported this mechanism of action.

These findings indicate that, in addition to its diuretic action, Lactuca indica exhibits secondary effects directly on epithelial cells which may protect against Escherichia coli infection. These properties might be useful for the development of alternative strategies in the treatment of UTI.